This invention relates to stepladders and more specifically to tripod or three-legged stepladders.
While stepladders have been in use for many years, they have traditionally been of the four-legged type. While four-legged support structures provide an adequate foundation, they must be used in conjunction with a level, horizontal support surface. Therefore, considerable problems exist when one attempts to utilize a stepladder on the ground or natural terrains, as for outside work.
There are very few attempts, known to applicant, to overcome this problem. Such attempts as are known are the approaches illustrated and described in U.S. Pat. Nos. 1,184,432 to Dueber; 3,356,180 to Parry; and 3,472,339 to Herrera. While these approaches generally disclose three-legged or tripod ladders, there are various undesirable characteristics in each that have been overcome by the present invention.
For example, in the Dueber patent, the guard or brace is not triangular, and therefore not as strong. Also, an elongated slot in which the guard B slides tends to weaken the rear leg, and the sides of the pail shelf do not diverge from the front rearwardly to prevent inadvertent folding or closure of the rear leg of the ladder. Thus if the notched corners slip loose the rear leg may inadvertently fold. In the Parry patent, there is actually disclosed a different type of stepladder, which is in reality more of a step stool and very limited in height. Further, there is no pail shelf at all and no means to prevent inadvertent folding of the ladder. The Herrera disclosure is directed to a stepladder that is placed into a lake or body of water for a fisherman to stand upon. It includes no triangular bracing for the legs, nor any pail shelf.
In the present invention there is provided a general purpose, tripod type stepladder which overcomes each of the aforesaid problems. Toward this end, a triangular bracing system utilizes a pair of straight or linear rods which connect a sleeve or collar that slides along the rear leg with each of the front legs or stiles. The steps between the stiles form the third leg of the bracing triangle. The rear leg is not slotted, notched, or weakened in any manner. The collar merely fits around the rear leg and slides up and down as the ladder is folded and unfolded.
The pail shelf is pivotally attached to the rear leg and formed of a pair of identically-shaped platform members which are separated or spaced apart to provide clearance for pivotal motion on either side of the rear leg. The rear portion of the platform members are connected by a rigid, U-shaped bracket while the front portions of the platform members remain spaced apart. The side edges of the platform members include forward portions thereof which diverge from front to rear. The diverging edges are of such dimension and configuration that when in the horizontal position, only the very forwardmost portion fits between the opposed stiles. The diverging configuration prevents forward movement of the pail shelf and thus inadvertent collapse or folding of the rear leg while the pail shelf is in the horizontal, pail-supporting configuration. Thus, the pail support serves as a safety device and actually forms a locking member to prevent inadvertent closure or folding of the ladder unless the operator removes any pails therefrom and positively folds the pail shelf to its vertical or closed position. Then, and only then can the rear leg of the stepladder be folded.
It is an object of the present invention to provide an improved general purpose tripod-type stepladder.
It is another object of the present invention to provide a tripod stepladder of the type described which includes an improved tripod bracing system.
It is a further object of the present invention to provide a tripod stepladder of the type described in which the pail shelf forms the locking member that prevents inadvertent closure or folding of the stepladder.